#include "stm32f10x.h"

int main()
{
//	RCC->APB2ENR|=1<<3;    //使能PORTB时钟	   	 
//	   	 
//	GPIOB->CRL&=0XFF0FFFFF; 
//	GPIOB->CRL|=0X00300000;//PB.5 推挽输出   	 
	/* 开启GPIOB时钟 */
	*(unsigned int*)(0x40021000+0x18) |= 1<<3;
	
	/* 配置PB0为推挽输出 */
	*(unsigned int*)(0x40010c00+0x00) |= 1<<(4*0);
	
	/* PB0输出低电平，点亮绿色LED */
	*(unsigned int*)(0x40010c00+0x0c) &= ~(1<<0);
	while(1);
}
